JP4191644B2 - Gas proportional control valve - Google Patents

Description

  The present invention relates to a gas proportional control valve that is provided, for example, in a gas supply pipe to a gas burner and controls increase / decrease of the gas supply amount to the gas burner.

  When controlling the amount of gas supplied to the gas burner from a small flow rate to a large flow rate, if one control valve mechanism is used to control the gas flow, the valve body must be enlarged to cope with the large flow rate. It becomes difficult to perform stably and accurately.

  Therefore, a small flow control valve mechanism that performs control in the small flow region and a large flow control valve mechanism that performs control in the large flow region are provided in parallel, and an electromagnetic on-off valve is provided downstream of the large flow control valve mechanism, A gas proportional control valve is known in which the electromagnetic on-off valve is closed to control the flow rate only by the small flow rate control valve mechanism when performing a small flow rate control (see, for example, Patent Document 1).

In addition, a flow control valve mechanism that controls the flow rate of a large flow rate and a constant flow rate mechanism that flows a constant small flow rate are provided, and a constant small flow rate is secured using the constant flow rate mechanism with the flow control valve mechanism closed. What was made to do is known (for example, refer patent document 2).
JP 58-37383 A (FIG. 1) Japanese Patent Publication No.7-113432 (FIG. 2)

  In the device described in Patent Document 1, although the gas flow rate can be stably proportionally controlled from the small flow rate to the large flow rate, the small flow rate control valve mechanism and the actuator that opens and closes the large flow rate control valve mechanism are provided. In addition, an electromagnetic on-off valve must be provided downstream of the large flow rate control valve mechanism, resulting in a problem that the entire gas proportional control valve is increased in size.

  On the other hand, in the thing of the said patent document 2, since an electromagnetic on-off valve is not used, the whole gas proportional control valve does not enlarge, but proportional control in a small flow area cannot be performed, and flow volume After the control valve mechanism is closed, only a constant small flow rate is ensured.

  In view of the above problems, the present invention has an object to provide a gas proportional control valve that can stably perform proportional control from a small flow rate to a large flow rate without using a separate mechanism such as an electromagnetic on-off valve. And

In order to solve the above-described problems, a gas proportional control valve according to the present invention includes a movable element that can freely move back and forth, and a flow rate control valve mechanism that increases the flow rate of gas as the movable element moves in the forward movement direction. In the gas proportional control valve, a small flow rate control valve mechanism that increases the gas flow rate in the small flow rate region as the mover moves from the movement start position, and the gas flow rate in the large flow rate region as the mover moves. At least one large flow rate control valve mechanism and when the amount of movement of the mover in the forward movement direction reaches a predetermined amount of movement, a part of the small flow rate control valve mechanism contacts the large flow rate control valve mechanism. mover in a state where the gas flow through the small flow control valve mechanism and a stopping means for stopping the movement of the movable element, the movement amount in the forward direction of the mover exceeds the predetermined amount of movement in contact The large flow control valve machine through the small flow control valve mechanism Transmitted to, and characterized by increasing the gas flow by the high flow control valve mechanism.

  When the mover starts moving in the forward movement direction, the small flow rate control valve mechanism is first opened to proportionally control the gas flow rate corresponding to the amount of movement of the mover. When the moving amount of the mover reaches a predetermined amount, the gas flow to the small flow rate control valve mechanism is stopped by moving the mover without using a separate mechanism such as an electromagnetic on-off valve. This stops the function of the small flow control valve mechanism. When the mover moves further in the forward direction, the large flow control mechanism that controls in the large flow region opens instead of the small flow control valve mechanism, so the gas flow continues to be proportionally controlled by this large flow control valve mechanism. Is done.

  By the way, the large flow rate control valve mechanism includes a valve body that is moved by a mover, and the small flow rate control valve mechanism is configured to be attached to the valve body of the large flow rate control valve mechanism. Can be further reduced in size.

  The small flow rate control valve mechanism includes a valve body that is moved by a mover. When the amount of movement of the mover in the forward movement direction reaches the predetermined movement amount, the valve body You may make it function as a stop means which obstruct | occludes a path | route and stops a gas flow.

  Both the small flow control valve mechanism and the large flow control valve mechanism are provided with a diaphragm type governor mechanism, and the number of parts can be reduced by configuring the diaphragm used in both flow control valve mechanisms as one member.

  As is apparent from the above description, the present invention includes a small flow rate control valve mechanism and a large flow rate proportional control valve mechanism, and further includes a stopping means for stopping the gas flow by moving the mover. Proportional control can be accurately and stably performed from a small flow rate to a large flow rate without increasing the overall size.

  Referring to FIG. 1, reference numeral 1 denotes a gas proportional control valve according to the present invention. This gas proportional control valve 1 has a small valve body 2 constituting a small flow proportional control valve mechanism and a large valve body 3 constituting a large flow proportional control valve mechanism. The small valve body 2 is housed in the large valve body 3 and is urged upward by a spring 21 that is contracted between the fixed plate 7 fixed in the large valve body 3. Further, the large valve body 3 is biased upward by a spring 31 which is contracted between the large valve body 3 and the bottom plate 1B.

  This gas proportional control valve 1 controls the gas flowing in from the gas inlet 11 to flow out from the gas outlet 12 by proportional control. In the state shown in FIG. 1, both the small valve body 2 and the large valve body 3 are in the closed position, which is the upper end position, and accordingly, no gas flows out from the gas outlet 12.

  An actuator 4 is attached to the upper portion of the gas proportional control valve 1. This actuator has a movable element 41 that can reciprocate in the vertical direction at the center, and an electromagnetic force that moves the movable element 41 downward by energizing a drive coil 42 that surrounds the movable element 41. The mover 41 is generated and moves downward. The electromagnetic force that moves the mover 41 downward can be freely adjusted by changing the duty ratio of the pulse power supplied to the drive coil 42.

  Referring to FIG. 2, when energization to drive coil 42 is started, mover 41 starts to move downward. The lower end of the mover 41 is in contact with the upper end 21 a of the small valve body 2, and an electromagnetic force that moves the mover 41 downward is generated, and the biasing force of the spring 21 and the primary pressure of the gas push up the diaphragm 51. When the resultant force becomes larger than the resultant force, the small valve body 2 is moved downward. Note that the biasing force of the spring 31 that biases the large valve body 3 upward is set to be larger than the biasing force of the spring 21, so that even if the small valve body 2 moves downward, in this state the large valve The body 3 does not move downward. Since the primary pressure of the gas acts on both diaphragms 51 and 52, if the area of the diaphragm 52 is larger than that of the diaphragm 51, the large valve body 3 moves downward even if there is no biasing force of the springs 21 and 31. There is nothing.

  When the small valve body 2 moves downward, the rubber valve packing 22 attached to the small valve body 2 in an annular shape is separated from the valve seat 30 formed on the inner periphery of the large valve body 3. Then, the gas that has flowed into the large valve body 3 through the vent 3 a formed in the large valve body 3 passes below the valve seat 30 through the gap formed between the small valve body 2 and the valve seat 30. Flowing.

  Since the gas passage 71 is formed in the center of the fixed plate 7, the gas passing through the gap between the small valve body 2 and the valve seat 30 wraps around the lower end of the small valve body 2 and passes through the gas passage 71. It flows into the large valve body 3 and flows out from the gas outlet 12 to a gas burner (not shown). The gap between the small valve body 2 and the valve seat 30 increases in proportion to the amount of forward movement of the mover 41 downward, and the gas flow rate passing through the gap also increases in proportion.

  The position of the small valve body 2 stops at a position where the downward electromagnetic force acting on the movable element 41 and the resultant force of the spring 21 and the force acting on the diaphragm 51 are balanced. Reference numeral 51 denotes a diaphragm made of a rubber thin film. When the primary pressure of the gas flowing in from the gas inlet port 11 fluctuates. For example, when the primary pressure rises, the diaphragm 51 receives a pressure increase of the primary pressure and turns the small valve. It functions as a governor that raises the body 2 upward. Then, the gap between the small valve body 2 and the valve seat 30 is reduced, and the secondary pressure flowing out from the gas outlet 12 is kept constant without fluctuation.

  A packing 72 constituting a stopping means is attached to the upper surface of the fixed plate 7. When the mover 41 moves further downward from the state shown in FIG. 2, the lower end of the small valve body 2 is pressed against the packing 72 as shown in FIG. 3. Then, even if a gap is formed between the small valve body 2 and the valve seat 30, the gas flow flowing through the gap to the gas outlet 12 is stopped.

  In this state, the lower end of the mover 41 contacts the washer 6 connected to the upper portion of the large valve body 3. Therefore, when the mover 41 moves further downward, the large valve body 3 is pushed downward through the washer 6 with the lower end of the small valve body 2 kept in contact with the packing 72.

  Referring to FIG. 4, the rubber valve packing 32 attached to the outer periphery of the large valve body 3 is in contact with the valve seat 10 in the closed state, but the large valve body 3 is in contact with the urging force of the spring 31 and the diaphragm 52. When the valve packing 32 is pushed down against the pushing force acting on the valve seat 32, the valve packing 32 is separated from the valve seat 10, and a gap is generated between the large valve body 3 and the valve seat 10. Then, the gas flowing in from the gas inlet 11 flows to the gas outlet 12 through the gap formed between the large valve body 3 and the valve seat 10, and flows out from the gas outlet 12. Since this gas flow rate is proportional to the size of the gap between the large valve body 3 and the valve seat 10, as the amount of forward movement of the mover 41 downward increases, the large valve body 3 and the valve seat. The gas flow rate between 10 and 10 increases.

  In this state, the large valve body 3 is stopped at a position where the downward electromagnetic force acting on the movable element 41 and the urging force of the spring 31 and the pushing force acting on the diaphragm 52 are balanced. Therefore, the diaphragm 52 functions as a governor, and even if the primary pressure varies, the size of the gap between the large valve body 3 and the valve seat 10 is automatically adjusted, and the secondary pressure does not vary.

  By the way, since the rubber valve packing 32 is attached to the outer periphery of the large valve body 3 as described above, in the state where the large valve body 3 is seated on the valve seat 10, there is a gap between the valve packing 32 and the valve seat 10. The airtightness of the is reliably maintained. Therefore, gas leakage does not occur between the large valve body 3 and the valve seat 10 in a state in which the small valve body 2 is opened, so that the governor characteristics by the diaphragm 51 are reliably exhibited.

  By the way, as shown in FIG. 5, the diaphragm 51 for exhibiting the governor function in the small flow control valve mechanism and the diaphragm 52 for the large flow control valve mechanism are integrally formed as a diaphragm body 5.

  Referring to FIG. 6, in FIG. 6, S indicates a change in the gas flow rate passing through the gap between the small valve body 2 and the valve seat 30 as the mover 41 moves forward, and L indicates the large valve body. The change of the gas flow rate which passes through the clearance gap between 3 and the valve seat 10 is shown.

  When the mover 41 starts moving forward from the movement start position, the gas flow rate increases along the curve S. When the point P1 is reached, the position of the mover 41 is moved all at once and moved to a point P2 on the curve L. That is, at this time, the small valve body 2 comes into contact with the packing 72 and the gas is switched to a state of passing between the large valve body 3 and the valve seat 10.

  When the gas flow rate is increased, the mover 41 is further moved forward, but when the gas flow rate is decreased, the gas passes through the point P2 and passes through the point between the large valve body 3 and the valve seat 10 until the point P3. When the gas flow rate is further reduced, the mover 41 is pulled up at a stroke and moved to the point P4. As described above, since the hysteresis is provided for switching between the small flow control valve mechanism and the large flow control valve mechanism, the occurrence of chattering at the time of switching is prevented.

  By the way, in the above-described embodiment, the flow area controlled by each of the two valve bodies of the small valve body 2 and the large valve body 3 is divided into the small flow area and the large flow area. The flow area controlled by one valve element may be further divided into the above areas. For example, as shown in FIG. 7, the first valve element 81, the second valve element 82, the third valve element 83, and the fourth valve element 84 are sequentially opened from the small flow area to the large flow area. Thus, it is possible to subdivide the flow area that each valve body is responsible for into four. The configuration shown in FIG. 7 is also an example, and may be divided into three flow rate regions, or may be further subdivided into five or more flow rate regions.

  In the above-described actuator 4, the mover 41 made of a magnetic material is used, but a linear actuator as shown in FIG. 8 may be used. In this device, the mover 9 made of a magnetic material serving as a core is provided with an N pole 91 and an S pole 92 at a predetermined interval, and magnetic poles 94 and 95 facing the N pole 91 and the S pole 92 are provided. And an electromagnetic coil 93 for exciting the magnetic poles 94 and 95. In the state shown in the figure, the magnetic pole 94 is excited to the S pole, and a current is applied to the electromagnetic coil 93 in the direction to excite the magnetic pole 95 to the N pole, so that the mover 9 can be biased downward.

  In addition, this invention is not limited to an above-described form, You may add a various change in the range which does not deviate from the summary of this invention.

The figure which shows the structure of one embodiment of this invention Diagram showing details of small valve body The figure which shows the operating state of the stop means Diagram showing the open state of the large valve disc Diagram showing the configuration of the diaphragm body Graph showing flow rate change The figure which shows the structure of other valve bodies Diagram showing another configuration of actuator

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas proportional control valve 2 Small valve body 3 Large valve body 5 Diaphragm body 10 Valve seat 11 Gas inflow port 12 Gas outflow port 21 Spring 30 Valve seat 41 Movable element 51 Diaphragm 52 Diaphragm 72 Packing

Claims (4)

In a gas proportional control valve equipped with a reciprocating mover and having a flow rate control valve mechanism for increasing the flow rate of gas as the mover moves in the forward movement direction, the mover moves forward from the movement start position. A small flow rate control valve mechanism for increasing the gas flow rate in the small flow rate region, at least one large flow rate control valve mechanism for increasing the gas flow rate in the large flow rate region as the mover moves, When the amount of movement in the forward direction reaches a predetermined amount of movement, a part of the small flow rate control valve mechanism comes into contact with the large flow rate control valve mechanism and the gas flow passing through the small flow rate control valve mechanism Stop means for stopping by movement, and in a state where the movement amount of the mover in the forward movement direction exceeds the predetermined movement amount, the movement of the mover via the small flow control valve mechanism transmitted to mechanisms, increasing the gas flow by the high flow control valve mechanism Gas proportional control valve, characterized in that.   The said large flow control valve mechanism is provided with the valve body moved with a needle | mover, The said small flow control valve mechanism is attached to the valve body of a large flow control valve mechanism. Gas proportional control valve.   The small flow rate control valve mechanism includes a valve body that is moved by a mover. When the amount of movement of the mover in the forward movement direction reaches the predetermined movement amount, the valve body moves through the gas flow path. The gas proportional control valve according to claim 1 or 2, wherein the gas proportional control valve functions as a stopping unit that closes and stops the gas flow. The small flow rate control valve mechanism and the large flow rate control valve mechanism are both provided with a diaphragm type governor mechanism, and the diaphragm used in both flow rate control valve mechanisms is constituted by one member. The gas proportional control valve according to any one of the above.

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